The truncated right circular cone has a large base radius 8 cm and a small base radius of 4 cm. The height of the truncated cone is 6 cm. How many $\text{cm}^3$ are in the volume of this solid?  [asy]

import olympiad; size(150); defaultpen(linewidth(0.8)); dotfactor=4;

draw(ellipse((0,0),4,1)); draw(ellipse((0,3),2,1/2));

draw((-3.97,.1)--(-1.97,3.1)^^(3.97,.1)--(1.97,3.1));

[/asy]
Explanation: [asy]
import olympiad; size(150); defaultpen(linewidth(0.8)); dotfactor=4;
draw(ellipse((0,0),4,1)); draw(ellipse((0,3),2,1/2),gray(.7));
// draw((-3.97,.1)--(-1.97,3.1)^^(3.97,.1)--(1.97,3.1));
draw((-3.97,.1)--(0,6.07)--(3.97,.1));

draw((4,0)--(0,0)--(0,6.07),linewidth(0.8));
draw((2,3)--(0,3),linewidth(0.8));
label("4",(2,3)--(0,3),S);
label("8",(4,0)--(0,0),S);
label("6",(0,0)--(0,3),W);
label("$x$",(0,2)--(0,6.07),W);
[/asy]

We "complete" the truncated cone by adding a smaller, similar cone atop the cut, forming a large cone.  We don't know the height of the small cone, so call it $x$.  Since the small and large cone are similar, we have $x/4=(x+6)/8$; solving yields $x=6$.  Hence the small cone has radius 4, height 6, and volume $(1/3)\pi(4^2)(6)=32\pi$ and the large cone has radius 8, height 12, and volume $(1/3)\pi(8^2)(12)=256\pi$.  The frustum's volume is the difference of these two volumes, or $256\pi-32\pi=\boxed{224\pi}$ cubic cm.